Wouldn't be a good idea to assigned them to a version so they will be more visible?

Why is visibility a problem? The "Issues" tab shows everything that's currently open.

Keep in mind that every change to an issue sends out an email to everyone that's subscribed to the tracker, so I would prefer not doing mass changes, especially if no new information is added in doing so.

What would be helpful is going through unconfirmed bugs, try to recreate them on your end, and post the result.